Air-brake mechanism.



No. 858,645. PATENTED JULY 2, 1.907.

G. H. BOSWELL. AIR BRAKE MECHANISM.

APPLICATION FILED MAY 23, 1906.

2 SHEETS-SHEET 1.

3607 74122 ,BOeSWbZZ, INVENTOR- ATTORNEYS GEORGE HAMILTON BOSWELL, OFALBANY, GEORGIA.

AIR-BRAKE MECHANISM.

Specification of Letters Patent.

Patented July 2, 1907.

Application filed May 23, 1906. Serial No- 318,363.

To all whom it may concern:

Be it known that I, GEORGE HAMILTON BOSWELL, a citizen of the UnitedStates, residing at Albany, inthe county of Dougherty and State ofGeorgia, have invented a new and useful Air-Brake Mechanism, of whichthe following is a specification.

This invention relates to air brake systems, and has for its principalobject to provide means whereby the braking pressure may be retained inthe brake cylinder during the recharging of the auxiliary reservoir, andfurther to so arrange the mechanism that when the engineers brake valveis placed on lap as is usual aiter either an emergency or servicereduction, communication will be opened up between the main reservoirand the train pipe in order to gradually recharge the train pipe and theauxiliary reservoirs Without waiting for the engineer to move his valveto running or release position.

A still further object of the invention is to provide a brake apparatusby which on a second reduction following closely a first application ofthe brakes, it will be possible to I obtain a braking pressure equal toor greater than the present emergency braking pressure.

A still further object of the invention is to so arrange and constructthe mechanism that it may be employed to advantage in connection withexisting Westinghouse or New York air brake mechanism with a slightchange in the engineers brake valve, the triple valves remainingunaltered.

With these and other objects in view, as will more fully hereinafterappear, the invention consists in certain novel features of constructionand arrangement of parts, hereinafter fully described, illustrated inthe accompanying drawings, and particularly pointed out in the appendedclaims, it being understood that various changes in the form,proportions, size or minor details of the structure may be made withoutdeparting from the spirit or sacrificing any of the advantages of theinvention.

In the accompanying drawings:Figure 1 is a sectional elevation of theretaining valve employed in connection with the triple valve for holdingthe pressure in the braking cylinder during the recharging of theauxiliary reservoir, the valve being shown in release position. Fig. 2is a similar view showing the valve in pressure retaining position. Fig.3 is a transverse sectional view of the valve on the line 33 of Fig. 1.Fig. 4 is a sectional elevation of the mechanism employed in connectionwith the engineers brake valve, the latter being shown in diagram.

Similar numerals of reference are employed to indicate correspondingparts throughout the several figures of the drawings.

In Fig. 1 is illustrated a triple valve A of the Westinghouse typeconnected in the usual manner to the train pipe B. From the exhaust portof the triple valve leads a pipe 10, said pipe being connected to thepressure retaining-valve forming the subject of the present invention,so that the exhaust from the brake cylinderv casing 15, whichis enlargedat one end to form a cylinder 16, the latter being closed by a suitablecap 17. In the cylinder is a bushing 18 within which is arranged an airtight piston 19, that is carried by a stem 20, the head of the stembeing designed to engage with the cap when the piston is moved to theposition illustrated in Fig. 2. The rear end of the spring extendsthrough the casing 15, and enters a guiding recess formed in a nut 22,that is screwed in the threaded opening at the rear end of the casing.On this stem is mounted a helical compression spring 23 that tends tomove the piston from the position shown in Fig. 1 to the position shownin Fig. 2, and the stress of the spring is adjusted slightly above theordinary auxiliary reservoir pressure, that is to say, if a workingpressure of sixty-five pounds is used, the spring will be adjusted toexercise a iorce of approximately sixty-eight pounds, and thus will tendnormally to keep the parts in the position shown in Fig. 2.

In the wall of the casing are two ports 26 and 27, and in theconstruction shown in Figs. 1 and 2 the port 26 is connected to the pipe10, while the port 27 opens to the outer air. These ports are formed ina valve seat that is arranged for the reception of a slide valve 30having a suitable cavity 31 by which the ports may be placed incommunication with each other when the valve assumes the position shownin Fig. 1; normally, however, the valve is in the position shown in Fig.2, and the port 26 is blanked. The valve is connected to the stem 20 bya suitable cross pin 33 that is held down to its seat by a spring 34 ofthe type usually employed for the main valves of triple valves.

1n the wall of the cylinder 16 are two ports 36 and 37, of which theport 37 alone is utilized when the device is employed in connection withthe triple valve, the port 36 being plugged. This port 37 is connectedby a branch pipe 38 to the train pipe B, and the piston is, there- Ifore, always exposed to train pipe pressure.

- In operation, the brakes being released, and the train pipe pressureentered through the port 37, the parts remain in the position shown inFig. 2 when the train pipe pressure is normal, in the present instancesixty-five pounds. The brakes may be applied by either service oremergency reduction in the usual manner, and if it is desired toimmediately release them, excess pressure is sent through the trainpipe, that it to say, a pressure of approximately seventy-pounds, andthis pressure will act on the triple valve in the usual manner to movethe valve to release position, and will, also, overcome the stress ofthe spring 22, and. will move the piston 19 to the position shown inFig. 1, so that the air issuing from the escape port to the triple valvemay pass through the pipe 10 to port 26, and thence through the cavity31 of the valve 30 and out through the port 27. Should the engineerdesire to recharge the auxiliary reservoir with out releasing the brake,he may place his valve in lap position and the air will gradually passto the train pipe, the pressure will be gradually brought up tosixty-live pounds, moving the triple valve to release position, so thattheair may pass through the usual feed groove oi: the main piston, tothe auxiliary reservoir, and replenish the supply. This pressure ofsixty-five pounds, however, is not suificient to move the piston 19against the stress of the spring 23, and the valve 30 will remain in theposition shown in Fig. 2, so that while the triple valve is in releaseposition, the air cannot reduce in the brake cylinder, and the brakeswill remain applied until excess pressure is sent through the train pipefor the purpose of moving the piston 19.

In order to permit the recharging of the auxiliary reservoirs while theengineers brake valve is at lap and the brakes are set, the retainingvalve and its casing are arranged as shown in Fig. 4. In this case thevalve 30 is reversed, so that the spring tends to move the valve in suchmanner that the cavity 31 will be placed in communication with the pipesand 52, and the spring in this case is set at a tension of sixty-livepounds. The inlet port 36 is placed in communication with a port 60leading lrom the casing of the engine ers brake valve by means of a pipe50, and in the valve proper is a curved port 61 which, when theengineers brake valve is in lap position will be in communication withthe main reservoir connection 62 of the engineers valve This permits theair under main reservoir pressure to pass gradually through the pipe 50to port 36, cylinder 18, thence through port 37, pipe 51, valve cavity31, pipe 52, to two pipes 63 and 64, one of which leads to a .pointabove the equalizing piston of the engineers brake valve, and the otherto a point below the equalizing piston of the brake valve. When theengineer moves his valve to lap position as he usually does aiter makingeither an emergency or a service reduction, the small port 61 will placethe pipe 50 in communication with themain reservoir connection, and airwill slowly feed from the main reservoir to the train pipe, passingpartly above and partly below the equalizing piston in order not todisturb the position of the latter, and the pressure will be graduallybrought up to sixty-five pounds in the train pipe, and in the retainingvalve, and in the triple valve. The triple valve will therefore move,as-above described, to release position, and the retaining valve, beingset at sixty-eight pounds,

] will not move to release position, so that the pressure will be heldin the brake cylinder, while the auxiliary reservoir is being recharged.when the auxiliary reservoir has received its full charge oi sixty-livepounds and the train pipe pressure is also sixty-live pounds. theslightest increase above this will cause the piston ill to descendagainst the action of the spring 22, and the port. 31 of valve 30 isallowed to move out of alinemcnt with the pipe 51, thereby cutting oilthe further llow of air from the main reservoir to the train pipe, sothat the recharging operation will be pcrl ectl y automatic.

It is obvious that the device maybe utilized in con nection with boththe triple valve and the engineeus brake valve, the structure remainingthesaine in both cases, with the exception that the position of thevalve is reversed, and one of the cylinder ports is at one time plugged,and at another time utilized for the possage of air.

I claim'.

1. A pressure controlling valve mechanism for use in connection withtriple valves or engineer's broke valves. consisting of. a casing havinga valve seat, provided with two ports that are disposed in :ilincinent.with cnch other in the direction of the length of the casing. the casinghaving at: one end a cylinder through the walls ol which extend twoports, one of which may be plugged when the device is used in connectionwith a triple valve. :1 piston titting within the cylinder. :1 slidevalve controlling the two ports of the casing, a piston rod having arigid connection with the slide valve, a spring surrounding the pistonrod and hearing :it one end against the piston. a recessed nut carriedby the casing and against: which the opposite end of the spring hears.the recess of the nut forming a guide for the end of the piston rod, and:1 spring arranged between the casing and the valve and tending to holdthe latter to its seat;

2. In air brake mechanism. on engineer's brake valve having an auxiliaryport movable into communiczition with the main reservoir connection whenthe valve is on lap. a valve casing, a valve therein, a cylinder incommuniciu tion with the casing, a piston in said cylinder andconnectedto the valve, a pipe lending between the engineeis brake valveand the cylinder, a second pipe leading from the cylinder to a portunder the control of said valve. :1 second pipe also under the controlot the valve. and connections between said second pipe and the upper andlower portions of the cylinder olf the equalizing piston.

In testimony thntI claim the foregoing us my own. I have hereto allixcdmy signature in the presence .ot two witness s.

GEORGE HAHN/[ION lltlSWlll ill.

Witnesses J. l. CHAMPION.

PAU L H. JloNns.

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